1. Field of the Invention
This invention relates generally to protection devices for radio equipment and more specifically to a protection device for transmitter-receiver.
2. Description of the Prior Art
In high frequency radio systems, a need exists for the protection of the components of the receiver and transmitter devices from high amplitude, short duration electromagnetic transients. These transients are capable of permanently damaging critical and sensitive circuitry in both the receiver and the transmitter. It is well known in separate transmitter and receiver units to protect the receiver from such transients. The prior art has not confronted the problem of protecting the transmitter. This is particularly critical in units where the transmitter and receiver use the same antenna.
In units where the transmitter/receiver uses the same antenna, relay or other circuit breaker type of circuitry has been used to protect the transmitter and receiver. These units are not sufficiently fast to prevent the transmission of high amplitude, short duration transients. Thus, there exists a need in the art to protect not only the receiver but also the transmitter in a single antenna unit. Since the transmitter is more sensitive to changes of capacitance in its output circuit, the devices of the prior art which were capable of protecting the transmitter from such transients also prevented the transmitter from transmitting. Thus, there exists a need for a protection device for a transmitter which will not interfere with its capability to transmit.